Culvert pipes are well-known and are commonly employed as a conduit for water drainage and management. Culverts are constructed of metal, concrete or polymer and may be formed into a variety of cross-sectional shapes. Culverts are typically placed at or under ground such as under bridges, roadways, etc. to allow water to pass through the culvert pipe from one side of the overlying structure to the other. Often it is desirable to allow water to more readily pass in a single direction through the culvert pipe. In such instances a flap gate can be installed at one or more ends of the culvert pipe.
An example of a known type of flap gate is described in U.S. Pat. No. 4,324,506, which issued Apr. 13, 1982 to Thomas J. Steinke. Another type of flap gate is described in U.S. Pat. No. 4,800,919, which issued Jan. 31, 1989 to Lothar Bachman. The entire content of each of the aforementioned patents is incorporated herein by reference.
One problem that exists in many known flap gate assemblies is that they are prefabricated to be mounted to a specific diameter culvert pipe. Often if the end of the pipe to which the assembly is to be mounted is misshaped, damaged or otherwise outside the acceptable mounting criteria it can be difficult or impossible to properly mount the flap gate assembly thereto. Given the often hard to reach locations of culvert pipes and the relatively cumbersome size and shape of most flap gates assemblies, correctively machining the assembly or pipe on site to correct the fit is often problematic or impossible. In addition, many known gate assemblies require multiple people (installers) to properly affix an assembly to a culvert pipe.
In light of the above, a need exists to provide an adjustable culvert gate assembly which has a greater tolerance of imperfect pipe mounting shapes/surfaces and diameters than known prefabricate gate assemblies, and which can be more readily mounted by a single installer.